JPH02223415A - Manufacture of resin molded product with skin - Google Patents

Abstract

PURPOSE:To contrive an improvement in visual quality, by a method wherein a top and bottom forces are clamped down, a flexible skin material is held through pinching by moving a slide core forward and then thermoplastic resin becoming a core material is pressed into a cavity between the bottom force and skin material. CONSTITUTION:A flexible skin material P1, which is shaped beforehand and becomes the skin, is arranged within a cavity 11 formed of the first and second bottom forces 4, 3, a top force 10 and a slide core 13. Then the top force 10 and bottom forces 4, 3 are clamped down and a flexible skin material P1 is held by placing between a protrusion l3a of the slide core 13 and a recessed part 4b of the bottom force 4 by moving the slide core 13 forward. Then rigid thermoplastic resin R becoming a core material is pressed into the cavity 11 among the bottom forces 4, 3 and skin material P1 under a molten state and a molded product where it is laminated by pressing the skin material P1 against the top force 10 is obtained. Visual quality of a product is improved like this and finish can be performed easily even if flashes are generated on an end part of the molded product.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to the production of resin molded products with skins for molding interior parts such as instrument panels, console box lids, and pillars installed in automobiles, for example. It is about the method.

[Prior Art] Conventionally, as a stamping mold for manufacturing a resin molded product with a skin, a mold as shown in FIG. 9 is known. That is, the second lower mold 23 is placed on the lower mounting plate 21 at the lower end with the spacer block 22 interposed therebetween. A first lower mold 24 is arranged on the second lower mold 23,
The first lower mold 24 is pushed upward by a spring 25.

An upper mold 27 fixed to an upper mounting plate 26 is arranged above the first lower mold 24 . A slide core 28 that is slidable in the left-right direction is supported at the lower part of the mold 27. Then, as shown in FIG. 9, the cavity 2
9 is formed.

As shown in FIG. 9, when the mold is opened, the molten resin R is injected onto the second lower mold 23, and a flexible two-layer skin +A' is formed on top of the second lower mold 23. P
Place +. Next, as shown in FIG. 10, the upper mold 27 integrated with the slide core 28 is lowered and clamped to the first lower mold 24.

Subsequently, when the mold is further clamped and the second lower mold 23 is raised, the molten resin R is pressed and spread out the lower surface of the skin material P1 and spreads to the end thereof, thereby forming the base material 32.

Next, after retracting the slide core 28, as shown in FIG. 11, the upper mold 27 is opened with respect to the first lower mold 24, and
The molded product is taken out by pushing it up with the push-up pin 30. A desired molded product is then obtained by rolling the ends of the molded product. The thus obtained console box lid as a molded product is made into a product by fixing the back side 1133 to the back side of the base material 32 molded with molten resin R with the heat sink 34, as shown in Item 13.

[Problems to be Solved by the Invention] However, in the above method for manufacturing a resin molded product with a skin, as shown in FIG. A so-called vertical paris 31 is generated along the plane (PL plane).

Therefore, when the end of the molded product is rolled up, the line of the end of the molded product cannot be finished neatly, resulting in poor appearance, or the pre-formed skin 'jA' P l is
There was also a problem in that it was difficult to peel it off from 2 and shave off the firmness 31 to finish it.

An object of the present invention is to provide a method for producing a resin molded article with a skin, which has an excellent appearance as a final product and can be easily finished even if flakes occur in the resulting molded article.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for manufacturing a resin molded article with a skin, which has an upper wall and a side wall bent and extending from the upper wall, and has a skin on the surface. , forming a cavity from a lower mold having a cavity forming surface on the back surface of the molded product; an upper mold having a cavity forming surface on the surface of the molded product; and a slide core having a cavity forming surface on the side wall end surface;
Providing a convex part on the tip of the slide core such that the cavity forming surface of the side wall end surface is extended, and providing a concave part corresponding to the convex part continuously at the end of the side wall cavity forming surface of the lower mold, After placing a flexible skin material that will become a pre-shaped skin in the cavity, the upper mold and the lower mold are clamped, the slide core is moved forward, and the flexible skin material is placed between the convex part and the recessed part. Then, a molten resin made of a hard thermoplastic resin serving as a core material was introduced into the cavity between the lower mold and the flexible skin material, and the molten resin was pressed against the skin material and laminated. A method of molding molded products is adopted.

[Function] By adopting the above means, in the mold open state where the upper mold is separated from the lower mold, a flexible skin material of a predetermined shape that has been shaped in advance is placed in the cavity, and then the mold is closed and the slide core is inserted. The mold is further clamped by sliding, and then a molten resin made of a hard thermoplastic resin is introduced into the cavity,
The molten resin is spread and laminated on the inner surface of the flexible skin material up to its ends. The molded product obtained in this way is
The convex part of the slide core and the concave part of the lower die control the size and direction of the flakes generated at the end of the molded product, and then the flexible skin material is moved inward from the end of the base material to be molded with molten resin. A product with a good appearance can be obtained by rolling it up.

[First Embodiment] An embodiment embodying the present invention will be described below with reference to FIGS. 1 to 7.

As shown in FIG. 1, a second lower die 3 that is movable up and down is arranged on the lower mounting plate 1 at the lower end via a spacer block 2. As shown in FIG. The second lower mold 3 has a convex cross section, and its protruding portion 3a is inserted into a through hole 4a provided in a first lower mold 4 disposed above the second lower mold 3. . The first lower mold 4 is urged upward by a spring 5 inserted into the through hole 2a of the spacer block 2 and the through hole 3b of the second lower mold 3.

When the first lower mold 4 is pushed up by the spring 5, as shown in FIG. 2, the second lower mold 3 and the first lower mold 4 are made of a hard thermoplastic resin as a core material. A pot portion 6 into which molten resin R is injected is formed. As this hard thermoplastic resin, polypropylene (PP), acrylonitrile-butadiene-styrene copolymer resin (ABS resin), etc. can be used. The first lower mold 4 and the second
The lower mold 3 has a cavity forming surface on the back side of the molded product.

A push-up plate 7 is arranged at the center of the lower mounting plate 1. The second lower mold 3 and the first lower mold 4 are provided with insertion holes 3c and 4c, respectively, and these insertion holes 3c and 4c
Inside is a push-up pin 8 whose lower end is supported by the push-up plate 7.
is inserted.

The push-up pin 8 is configured to push up the molded product P2 and release it from the first lower mold 4 after molding the molded product P2.

On the first lower mold 4, an upper mold 10 is arranged, which is fixed to an upper mounting plate 9 at the upper end and can be moved into and out of contact with the first lower mold 4. The same mold 10 has a cavity forming surface on the surface of the molded product. The first lower mold 4 and the upper mold 10 form a cavity 11 in which a molded product P2 of a predetermined shape is molded. In the cavity 11, a flexible skin material P that forms a skin that has been previously shaped by vacuum forming is placed. Between the first lower mold 4 and the upper mold 10, a slide core 13 that can be slid in the left-right direction by a hydraulic cylinder 12 is supported by a mounting member 14 fixed to the upper mold 10. The slide core 13 has a cavity forming surface on the side wall end surface of the molded product.

A convex portion 13a having a substantially trapezoidal cross section is formed at the inner end of the slide core 13. The convex portion 13a is a molded product P2.
The cavity forming surface of the end face of the side wall is shaped to be extended. A concave portion 4b having a shape corresponding to the convex portion 13a is provided in the first lower die 4 at a position corresponding to the convex portion 13a. The recess 4b is formed continuously at the end of the side wall cavity forming surface of the first lower mold 4. As shown in FIG. 5, the convex portion 13a of the slide core 13 and the concave portion 4b of the first lower die 4 restrict the direction in which the firmness generated at the end of the molded product P2 extends.

A method for manufacturing a skinned resin molded product using the stamping mold configured as described above will be described.

As shown in FIG. 2, first, in an open state in which the upper mold 10 is separated from the first lower mold 4, the first lower mold 4 is lifted relative to the second lower mold 3 by the action of the spring 5. A molten resin R made of a hard thermoplastic resin is injected into the pot portion 6 formed in this state. Next, a flexible skin material P1 having a two-layer structure in which a skin 15 made of foamed polypropylene and an outer skin 16 made of soft vinyl chloride resin are adhered is placed thereon. Note that cloth or the like can also be used as the skin 15.

Next, as shown in FIG. 1, the upper mold 10 is lowered and the first
The mold is closed so that the space between it and the lower mold 4 is closed. Subsequently, the hydraulic cylinder 12 is operated to move the slide core 13 forward. Then, the convex portion 13a at the tip of the slide core 13 is engaged with the concave portion 4b of the first lower mold 4. At this time, the skin material P1 has an upper surface 13c of a convex portion 13a provided to extend from the molding surface of the cavity 11 and a lower surface 4d of the recessed portion 4b.
It will be in a state where it is strongly compressed and pinched between.

Next, as shown in FIG. 3, the second lower mold 3 is pushed up by further clamping the mold. Then, the molten resin R in the pot part 6 is pressed and gradually becomes a flexible skin material P.
, extends along the inner circumferential surface of the skin material P1 to the end of the skin material P1. Then, when the second lower mold 3 is pushed up until it comes into contact with the first lower mold 4, the upper end surface of the protrusion 3a of the second lower mold 3 and the upper end surface of the first lower mold 4 become flush, and the melting The resin R is formed to a substantially constant thickness over the entire inner peripheral surface of the skin material P1, and becomes the base material 17 of the molded product P2.

Next, when the upper mold 10 is slightly raised, the first lower mold 4 is slightly raised under the action of the spring 5 in the clamped state, and the clamping force is reduced. In this state, the slide core 13 is moved backward by the action of the hydraulic cylinder 12, and the slide core 13
The convex portion 13a is separated from the concave portion 4b of the first lower mold 4.

Next, the upper mold 10 is raised and separated from the first lower mold 4 to open the mold. Then, as shown in FIG. 4, the push-up plate 7
By raising the push-up pin 8, the molded product P2 is released from the first lower mold 4. In this way, the outer skin 1
A molded product P2 with good adhesion is obtained in which the skin material P1 consisting of the molded resin 6 and the skin 15 and the base material 17 obtained from the molten resin R are directly joined. This molded product P2 has an upper wall and a side wall extending bent from the upper wall, and has a skin on its surface.

The skin 15 of the obtained molded product P2 is molded from foamed polypropylene as described above, and since the foamed layer is not easily crushed, a good soft texture is exhibited. The reason for this is that in stamping molding with the bottom part 6, the pressure of the molten resin R is 30 to 10 kg/cJ, which is considerably lower than the internal pressure of 300 to 500 kg/cJ in injection molding. .

As shown in FIG.
However, the upper surface of the convex portion 13a of the slide core 13 and the first lower mold 4
The direction in which the firmness extends is regulated by the lower surface of the recess 4b, and its tip extends inward from the inner circumferential surface (PL surface) of the base material 17. Therefore, the skin material P1 at the end of the molded product P2 can be easily rolled inside (=inner peripheral surface of l17) as shown in FIG. A product P3 as a console hook lid having good properties is molded. In this case, even if a slight bulge 18 occurs at the end of the base material 17 due to stamping molding,
The burr 18 is not in the extending direction of the inner peripheral surface of the base material 17,
Since the direction is substantially perpendicular to this direction, the appearance of the product P3 after the skin material P1 is rolled up will not be impaired.

Also, when removing the bulges 18, since the direction of the bulges 18 extends in a direction perpendicular to the inner circumferential surface of the base material 17, the process is easy.

As described above, according to the method for manufacturing a resin molded product with a skin using the stamping mold of this embodiment, the molded product P
A convex portion 13a is provided at the tip of the slide core 13 disposed at a position corresponding to the end of the slide core 2, and a concave portion 4b is provided in the first lower mold 4 at a position corresponding to the convex portion 13a. Since the skin 'rA' P 1 at the end of the molded product P2 extends in the inward direction perpendicular to the inner peripheral surface of the base material 17, when the end of the skin material P1 is rolled up, the burr 18 forms on the product P3.
There is no risk of damaging the appearance of the burr, and even if burrs 18 occur, they can be easily disposed of.

[Second Example] In this example, the positional relationship between the lower mold 4, the upper mold 10, and the slide core 13, that is, the shape of the side wall end surface of the molded product P2 was changed, and the slide core 13 was attached to the lower mold 4. Other than that, the structure was the same as that of the first embodiment.

As shown in FIG. 8, a skin material P1 consisting of a skin 15 and an outer skin 16 is placed in the cavity 11, and a lower mold 4 and an upper mold 1 are formed.
0 and the slide core 13 are closed, the oblique part 13b of the slide core 13 forms the end face of the side wall of the molded product P2, and the convex part 13a of the slide core 13 and the concave part 4b of the lower mold 4 form an extension of the same side wall. (the inverted letter-shaped portion in FIG. 8) is formed. The skin material P1 is strongly compressed and held between the upper surface 13C of the convex portion 13a provided so as to extend from the molding surface of the cavity 11 and the lower surface 4d of the recessed portion 4b.

With this configuration, the skin material P.

When the molten resin R is introduced into the cavity 11 between the molten resin R and the lower mold 4, whether or not more flaking occurs at the side wall end of the base material 17 formed by the molten resin R than in the first embodiment; Even if burrs are generated, the direction of the burrs is toward the back side of the base material 17, so that it is easy to roll the skin material P onto the back side of the base material 17, and the appearance is also good.

The present invention is not limited to the embodiments described in L, and can be arbitrarily modified without departing from the spirit of the invention. For example, it can be configured as follows.

(1) In the above embodiment, in order to press the molten resin R in the bottom part 6 to mold the molded product P2, the second lower mold 3
was pushed up to make the upper end surface of the protruding portion 3a and the upper end surface of the first lower mold 4 the same plane, and the molten resin R was formed to a substantially constant thickness over the entire inner circumferential surface of the skin +A'P1. However, the second lower mold 3
The upper end surface of the protrusion 3a and the upper end surface of the first lower mold 4 do not have to be on the same plane, and the molten resin R does not have to have a constant thickness over the entire inner circumferential surface of the skin material P. It can be set appropriately depending on the shape of the intended molded product P2.

(2) In the above embodiment, the upper mold 10 has a movable mold function, and the first lower mold 4 has a fixed mold function, but conversely, the upper mold 10 has a fixed mold function. Alternatively, the first lower mold 4 may have a movable function.

(3) In the above embodiment, the pot part 6 was formed from the first lower mold 4 and the second lower mold 3, and the molten resin R was injected into the pot part 6, but this pot part 6 was not provided. For example, injection molding or transfer molding can be performed by providing a gate communicating with the cavity 11 in the first lower mold 4.

(4) In the above example, the lid of a console box was molded as product P3, but it is also possible to manufacture products that wrap around the ends of molded product P2, and can also be used to manufacture products such as instrument panels and pillars. Applicable.

[Effects of the Invention] According to the method for manufacturing a resin molded product with a skin of the present invention, a molded product that has an excellent appearance and is easy to finish even if flakes occur at the edges of the molded product can be obtained. It has the effect of being

[Brief explanation of the drawing]

1 to 7 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a sectional view showing a stamping mold in a closed state, and FIG. 2 is a sectional view showing a stamping mold in an open state. A cross-sectional view showing the mold, FIG. 3 is a cross-sectional view showing the stamping mold with the slide core advanced, and FIG. 4 shows the stamping mold with the mold open and pushing up the molded product. 5 is a sectional view showing the structure for forming the end of the molded product, FIG. 6 is a sectional view showing the end of the product with the molded product wrapped around it, and FIG. 7 is a sectional view showing the product. Figure, 8th
The figure shows the second embodiment, and is a cross-sectional view showing the structure of the reservoir forming the end of the molded product. Figures 9 to 13 are diagrams showing the conventional example, and Figure 9 is stamping molding with the mold open. Figure 1θ is a cross-sectional view showing the stamping mold in a clamped state, Figure 11 is a cross-sectional view showing the stamping mold in a state of pushing up a molded product, and Figure 12 13 is a cross-sectional view showing the end of the molded product, and FIG. 13 is a cross-sectional view showing the molded product assembled into the M lid. 3... Second lower mold as a lower mold, 4... First lower mold as a lower mold, 4b... Recessed portion, 10... Upper mold, 11...
・Cavity, 13...Slide core, 13a...
Convex portion, Pl... skin material, P2... molded product, R...
Molten resin made of hard thermoplastic resin

Claims (1)

[Claims] 1. A method for manufacturing a resin molded product with a skin, which has an upper wall, a side wall extending bent from the upper wall, and a skin on the surface, a lower mold having a cavity forming surface on the back side of the molded product (4,
3), an upper mold (1) having a cavity forming surface on the surface of the molded product;
0) and a slide core (13) having a cavity forming surface on the side wall end surface, and a cavity (11) is formed from the slide core (13) having a cavity forming surface on the side wall end surface, and the cavity forming surface on the side wall end surface is extended to the tip of the slide core (13). Convex part (13a
), and a concave part (4b) corresponding to the convex part (13a) is provided continuously at the end of the side wall cavity forming surface of the lower mold (4).
), and after arranging a flexible skin material (P_1) that will become the pre-shaped skin in the cavity (11), the upper mold (10) and the lower mold (4, 3) are clamped, and the slide core(
13) and move the convex portion (13a) and concave portion (4b) forward.
A flexible skin material (P_1) is sandwiched between them, and then a lower mold (
By introducing a molten resin (R) made of a hard thermoplastic resin as a core material into the cavity (11) between the molten resin (4, 3) and the flexible skin material (P_1), the molten resin (R) is
A method for manufacturing a resin molded article with a skin, characterized in that R) is pressed onto the skin material (P_1) to form a laminated molded article (P_2).